Electric heater



Nov. 6, 1928.

D. U. POWELL ELECTRIC HEATER I Filed Oct. l0, 1927 TCT nwwtoz y f 1&0/ Z,

jar/fafa 7i PatentedL Nov. 6, y1,928. i

PATENT oFFICE.

DALTON U. rownnnorwoonsnnnn, ome, .assIeNony orf oNn-'Tn'innro sAmuEn x.

` FRANK AND ONE-.THIRD TovnA'z'L.- nAvIs, oF WHEELING, WEST VIRGINIA.

. ELECTRIC HEATER;

f Application iiled Octobclf 10, 1927. lSerial No. 225,354.

The inventionaims to provide a new and generally improved electric heater which may beadvantageously used for a widefvariety of uses, novelprovision being made "whereby no liquid kor even' moisture may enter the rheater casing to 'produce any undesirableresults.

The heater casing is equippedxwith a cur# i rent-conducting cable, and furtherobjects of theinvention are to provideunique means for tightly securing thiscable and the casing together; and to' provide an effective packing around a portion of the kcable to prevent possible entr of moisture or liquid. n Another ohject of the inventionis toprok vide a sectional. constructionfwhich may be y easily and inexpensively manufactured and ma f readily be produced in different sizes f wit `iout alterations as to details of construction.-

improved heating element for'use in thecas` ing, a novel `process being employed to form a curved heating element,v` withan unusual length of resistance wire, should such an element be desirable. f

ylVith the foregoing and view, the inventionresides in the novel subject hereinafter described yand claimed, the

description being supplemented companying drawings.

by the ac- Fig. 1 is a longitudinal sectional` v iew` partly' in elevationI showing one form ofcon-k struction. f

Ffgf2 is an enlarged longitudinal sectional View partly in elevation. l se section al views f Figs. Sand 4 'are transver on the correspondingly numbere(l flinesgof Final. 1

igs. 5 and 6 arefsectional views'at right angles to each other showing amodiiied form of construction, portions of Fig. 6 being in elevation.' j f f ,y

Figs. 7 and S are transverse sectional views on lines 7--7 andS-S of Fig. 5; 4B'

. further modified form of construction; Figs. f1() and 11are side elevations showing y.different ways in which the heating element may be constructed. Y

1 to 4,12 denotes alowertube closed at its lowerend by a plug 13 andiuid-tightly c onnected at its upper vend by'k an appropriate Yet'another-aim-is to produce a new and m'inor objects in Fig.' 9 is a sind@` e1evaa0n-paiowing af ani" end of the passagelS'. When this device 30 "In the form of construction shown in Figs.

drical body 16 whose upper end constitutes aY neck which is longitudinally tapered and is rendered contractible and expansible by providing it' withlongitudinal slits 17; A pas sage 18 extends longitudinallythrough the body 16 andfhas its inner end portion of `greaterdiameterzthan its outer end portion,-

end bent laterally out-ward as at 21 between 'y the shoulder 19 and the inner end of the body 16. This cable also embodies a sheath 22 of lead. orother desired material disposed within the armor 2O and projecting inwardly beyond the saine, the current conducting wires 23'being housed within said sheath andappropriatelyinsulated from each other.

AA nut or cap k2,4 vis threaded vupon the ne'ck-k 175' forming upper end ofthe body 16 and is internally tapered for the purpose of tightly contractingthe neck around the cable C to 7 assist in establishing a tenacious connection between the heater casing andthe cable.y The f outwardly ybent end 21 of thecable armor is also ytightly clamped to complete this tenacious connection, and provision ismade for tightly packing thespacebetweenthe sheath 22 andthe wall of the. passage 18, preventing 'entrance of moisture or liquid.

In the present showing, a clamping collar 25 is disposed in the inner portion'of the pasg sage 18, between the shoulder 19 and the lat-r erally bent armor end 21, and a second clamping collar 26 is coioperable with said collar 25 inclampingk said armor end 211. vA p'ackingcontracting collar 27 surrounds't-he projecting sheath end 22 and contacts with the'colp lar 26,l` a second packing-contracting collar 28 4surrounds said sheath end 22inr spaced relation with the collar 27, ain appropriate packpressing device 30 is threaded finto the inner is tightened, it forces all of the annular means 28-29-274-26-25 toward the 'shoulder '19. Hence, the collars 25`26 are made to tightly hold the outwardly bent armor end 21, and the 'collars 27-'28 are caused to compress the "packing 29 causing it tostightly engage the 'sheath 4end y22'and the, wall ofthe'passage 158.` 'f

Appropriate locking means such as a screw y ing 29 surrounds said sheath end 22` between'` 'i vthe two -collars 27-28, andajpacking-com- 3l may be provided for holding thedevice 30 in adjusted position. a

The wires 23 enter metallic coupling tubes 82 which are mounted in an insulating and heat-resisting block 33 in the tube l5. Other conducting wires 34 extend into these tubes and lead to an electric heating element H in the tube l2, the wires 23-34 being secured in the tubes 32, by binding screws 36. The heater H is of substantially cylindrical form and to add to the eiiiciency of this heater, a metallic core 37de preferably provided in the same. `This heater is preferablyconstructed in a manner hereinafter' described.

The heater shown has both termina-ls at its f upper end and is used in a. two-wire circuit. If such a heater is to be usedand the current returned through a metallic portion of the cable C. instead of through one of the wires 84, one terminal of the heater may be connected to the device 30 by a binding screw 38, or a ground connection could be provided with some other metallic part of the heater casing.

If the cable C be provided only with one wire and the terminals of the heater H be disposed one at the upper end of said heater and one at the lower. end thereof, said wire may be connected with the upper terminal and the lower terminal may be connected with the tube 1Q by an appropriate binding post or the like such as that indicated at 39 in Fig. l. Figs. 5, 6, 7, 8 and 9 show the provision which may be made for using a fiat heater H instead of a oylindricalheater. In Figs. 5, G, 7 and 8, a tube lQL having a Hat portion 12b, is provided for the heater H', the upper end of this tube being threaded directly into the tube l5 if desired, instead of using a coupling such as 14. With the exception of the flattened portion 12b and the provision for connecting the tube 12a with the tube l5, this tube may be considered as substantially identical with the tube l2. y

The tube 12C shown in Fig. 9 is very similar to the tube 12a but its. attened portion 12d may be closed by a plate or the like welded in place, instead of enlarging said end and closing it with a plug as in Figs. 5` and 6.

In forming either the heater H or the heater H', I make use of a central strip of mica or other appropriate insulating material 40. Around this strip, I wrap ribbon wire 41 so as to provide reaches of this resistance wireat opposite sides .of saidstrip, and the terminals of the wire may be both disposed upwardly as in Fig. Vl0, or one upwardly and one downwardly as in Fig. ll,

Against the outer sides ofthe above-named reaches of the wire 4l, I place additional strips 42 of mica or other appropriate insulating material. Then, the three strips 40--42 and the resistance wire 4l are encased in a. thinmetal casing 43 to retain them tightly assembled. All of these assembly' steps are `His to be produced, the entire assembly formed by the parts 40-41-42*43, is rolled or yotherwise curved after such assembly is complete. Thus,-the desired curved or cylindrical formation is imparted to the heater and it will be observed that suchk heater possesses resistance reaches near both its inner and outer peripheries, so that its efficiency is much greater than can be obtained from cy lindrical heaters in which an insulating core l is provided, around which the resistance wire is merely wrapped, providing no resistance wire at the inner periphery7 of such core.

rlhe invention is of great advantage for heating oil wells to increase production by dis-` solving at any depth, the paratline and other gummy substances existing in wells. This heater may be used both for complete immersion and as a space heater. It will be observed that the cable C will advantageously carry `the entire weight of the parts connected with its lower end, serving also to conduct current to the heater. Any entrance of oil or the like into the heater casing is prevented by the novel. packing means andV it will be observed that such means also acts to some extent to provide an effective Weight supporting connection between cableand casing.` A cable such as that shown is preferably employed, but in some uses of the invention, cables provided fithcoverings of non-metallic materials may be used and when this is done, the armor clamping means such as 2:5-26, may possibly be replaced with additional packing means.

The invention is rather simple and inexpensive, yet is practical and advantageous, not only from the standpoint of use, but from a manufacturing and commercial standpoint.

On account of the excellent results obtainable from the details disclosed, they are prefy erably followed. However, wit-hin the scope of the invention as claimed, numerous variations may be made.

I claim l. In an electric heater, a casing for a heating element, 'said casing being provided with Va longitudinally split contractable and expansible neck tok receive a cable for conducting current to the heating element, said neck being tapered at its outer end and externally threaded, and an internally tapered nut threaded on said tapered neck portion for tightly contracting it around the cable.

2. In an electric heater, a casing for a heating element, said casing being provided with an outwardly projecting contractable neck, with a cable-receiving passage extending lon-` gitudinally through said neck, and with an lou inwardly facing shoulder between the endsof 3. In an electric heater, a casing for a heating element, said casing beingr provided with a cable-receiving passage, a'cable extending into said passage for conducting current to the heating element, said cable having an armor whose inner end is bent outwardly in the passage and being provided also with a sheath within the'arinor projecting beyond said outwardly bent end of said armor,-annular means in said passage `for clamping said outwardly bent armor end, additional annular means in said passage surrounding said projecting portion Vof said sheathfand en'ibodying packing means, a stationaryshoulder'in the passage' 'for limiting movement of said annular means in one direction, and a thrust device mounted in said passage or'forcinglsaid annular means toward said shoulder.

4. In an electric heater, a casing for a heating element, said casingbeing provided with .an outwardly projecting contiac'table neck,

with a cable-receiving passage extending longitudinally through said neck, and with an inwardlyfacing shoulder between the ends of said passage, a cable passing into said passage and having an armor whose inner end is bent outwardly and disposed between said shoulder and the inner end ofthe passage, said cable being provided also with a sheath which projects inwardly beyond said bent armor end, annular means in the passage for clamping said outwardly bent armor end, additional annular means in said passage surrounding said projecting portion of said sheath and embodying packing means, meansin the inner end of said passage for iorcing said an- `iiular means toward said shoulderto operative position, and means for contracting said iicck around the cable armor.

5. An electric heater comprising` a tube vclosed at its lower end and internally threaded at its upper end,.a tubular cylindrical body having its lower end threaded into the upper end of said tube, the upper end of said body being split and tapered for contraction tightly aroundl a current conducting cable, a nut threaded on said splity tapered endV for contracting said end, cable-engaging packing means in said body, and means for compressing said packing means to cause tight contact thereof withv the body and cable;

In testimony whereof I have hereunto affixed my signature. f DALTON U. POWELL. 

